Railway signaling system.



G. J. COLEMAN.

RAILWAY SIGNALING SYSTEM.

APPLICATION I'ILED JULY 24,1906.

Patented May 19, 1914.

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k u w coLpMBIA PLANOORAPH COL,WASHINGTON, D. t.

UNITED STATES PATENT OFFICE. I

CLYDE J. COLEMAN, OF NEW YORK, N. Y., ASSIG-NOR TO THE HALL SIGNALCOMPANY,

' A CORPORATION OF MAINE.

RAILWAY SIGNALING SYSTEM.

Specification of Letters Patent.

Patented May 19, 1914.

Application filed July 24, 1906. Serial No. 327,557.

T 0 all whom it may concern Be it known that I, CLYDE J. COLEMAN,

a citizen of the United States,'residing at and useful Improvements inRailway Signaling Systems, of which the following is a specification,reference being had therein to the accompanying drawing, forming a partthereof.

My invention relates broadly to railway traffic-controlling apparatus,such, for instance, as traflic-controlling apparatus which governs themovement of trains or railway vehicles by the display of visualsemaphore signals, and as to certain features my invention relatesparticularly to home-anddistant railway block signaling apparatus. Alsoas to certain features my invention relates particularly totraf1ic-controlling or signaling systems for electric railways.

Generally designated the objects of my invention are reliability andeconomy in operation, simplicity and economy of construe tion, andsimplicity and economy in maintenance.

It is a particular object of my invention to economize in consumption oftraffic-controlling or signaling currents in traiiic controlling railcircuits which include as conduc-' tors the track rails of the railwayin order that such rail circuits may be governed by the passage of atrain or railway vehicle along the track.

Another object which may be especially designated is to economize in theinstallationcost of the sources of traflic-co-ntrolling current for suchcircuits, particularly when such sources are embodied in alternatingcurrent transformers for supplying alternating traflic-controlling orsignaling current to the traflic-control ing or signal-controlling railcircuits of electric railways.

To the foregoing ends my invention broadly comprehends many features, afew of which will now be enumerated, while many others will appear inthe light of the complete description following this pream- Me.

My invention comprehends the combination of two electro-translativedevices or relays connected with the track rails at points on therailway separated by a considerable distance, the relays in theillustrated embodiment being thus connected with the track ralls throughinterposed static receiving transformers, and a common source oftraflic-controlling or signal-controlling electric current connectedwith the track rails at a point between the connections of theelectro-translative devices therewith, so as to feed traffic-controllingor signaling ourrent through the track rails in opposite directions andto both such electro-translative devices or relays in common, theelectrotranslative devices being arranged in control of suitabletraflic-controlling apparatus or signals governing traflic along therailway, and such a source of traffic-controlling or signaling currentbeing embodied in a static supply transformer in the illustrated exampleof my invention.

In the illustrated embodiment of my invention the twoelectro-translative devices or relays receive trafiic-controlling orsignaling current from the termini of the rails of a given block orsection of the railway track, the source of traffic-controlling currentfor such section being connected to the rails thereof at a point midwaybetween the ends ofthe section, and in the illustrated embodiment bothsuch elect-ro-translative devices commonly control one trafliccontrolling or vention the receiving transformers which receivesignaling current from the termini of the block rails and deliversignal-controlling current to the signahcontrolling relays, have theirprimary coils arranged and adapted to act as conductive cross-bondsbetween the opposite rails of a given block or section for cross-bondingconduction of traction current flowing through the track rails as returnpaths, such primary coils in this specific instance being also arrangedand adapted to act as conductive section bonds to conduct such returntraction current from the rails of one block or section to the rails ofthe next adjacent block or section; and in this particular instance thesecondary coil of each supply transformer which feeds signal-controllingcurrent to the rail circuit of a block is also arranged and adapted toact as a conductive cross-bond for the conduction of traction currentbetween the opposite rails of such block.

In traflic-controlling or signaling rail circuits such as mentionedabove, the loss of electrical energy by leakage of traflic-controllingor signaling current, from rail to rail through the rail ties and theground, is not merely proportionate to the distance of transmissionthrough the rail circuit from the source of current to the point whereit is received from the rails by the electro-translative device, but, ifsuch distance of transmission or length of rail circuit be increased bya given ratio, the electrical losses incurred by such leakage of currentwill be increased in a much greater ratio; and, conversely, if suchdistance of transmission be decreased in any given ratio, the electricallosses will in consequence be disproportionately decreased, so that, byplacing a source of tratlic-controlling current in the middle of a blockand thus reducing the distance of current transmission to one-half, Ihave succeeded in eii'ecting a very considerable saving of electricalpower and a very'considerable increase in efiiciency. And all this isparticularly true in its application to cases wherein alternating orperiodic tIflfl'lC-CO11- trolling or signaling current is employed inthe traiiic-controlling or signaling rail circuit, because in such casesthe ohmic resistance of the circuit is supplemented by the inductiveresistance or counter electro-motive force of self-induction in the irontrack rails and through portions of the complete circuit so as toincrease the proportion or percentage of leakage current which passesfrom rail to rail through the leakage paths or circuit-branches whichare substantially non-inductive resistances.

In the diagram I have illustrated an ad aptation of my broad inventionto a home-anddistant block signaling system for an electric railway. Thediagram indicates a succession of signaling blocks or sectionsdemarcated by successive home and distant signaling apparatuses A, B andC.

M and N represent the track rails. The track rails of adjacent sectionsare insulated from each other in the usual way by interposition ofinsulations located substantially at the signal posts.

Step-up receiving transformers, such as 15, 15 and 15, have theirprimary coils, such as 16, 16 and 16, bridged across the rails ofsuccessive signaling blocks at the advance ends of such blocks; andsimilar step-up receiving transformers, such as 18, 18 and 18 have theirprimary coils, such as 17, 17" and 17 similarly bridged across the railsof the successive signaling blocks at the rear ends of such blocks. Thusare provided, at the junctures of the adjacent blocks, two receivingtransformers, the primary coil of one being connected in the rear end ofthe rail circuit extending in advance and the primary coil of the otherbeing connected in the advance end of the rail circuit extending inrear, and these primary coils also have their neutral points connectedtogether by suitable conductors as indicated, whereby such primary coilsnot only act as traction current cross-bonds between the opposite trackrails, but also actas traction current section bonds for conductivelyconnecting the track rails of adjacent sections. Stepdown supplytransformers, such as 3 3' and 3, have their secondary coils, such asat. at and 4, bridged across the rails of the successive blocks atpoints substantially in the middle of such blocks. These secondary coilsare preferably of such length and crosssection as to constituteeffectual traction current cross-bonds between the opposite track rails.

The t'ain D is represented in the block in advance of the signals C andthe electric traction system can be clearly understood by tracing thetraction circuit for this train, which is as follows: from one terminalof the traction current generator I, which in the present instance isrepresented as a direct current generator, through the trolley wire Kout along the railway to the point where the train D is located, andthence through the trolley wheel G carried by such train, conductorconnected to such trolley wheel, motor field F, motor armature E,current conductor leading to the axles and wheels D, and from suchwheels to the track rails M and N, and through such track rails, inparallel, rearward to the rear end of the signaling block upon which thetrain is located, and thence through the two divisions of the primarycoil 1'? demarcated by its neutral point, and thence through thesection-bonding connection to the neutral point of the primary coil 16,and thence in parallel through the two halves or sections of suchprimary coil to the rails M and N of the block BC, and thence rearwardthrough such rails in parallel to the rear end of such block BC, andthence in parallel through the two sections of the primary coil 1'? ofthe receiving transformer 18 and from the neutral point of such coil 17through the section-bonding conductor to the neutral point of theprimary transformer coil 16*, and so on rearward through the block ABand through the two sections of the primary ductor L, the oppositeterminals of such signaling generator J being connected re spectively tosuch trolley wire K and extra line conductor L. The primary coils of thesupply transformers are connected with this signaling current supplytransmission line K, L, by suitable branch conductors, such as 6, 7 and6 7 and 6, 7.

The signal-controlling currents delivered by the secondary coils of thesupply transformers traverse the track rails in opposite directions fromsuch secondary coils to the opposite ends of their respective blocks andthrough the primary coils of the receiving transformers connected withthe termini of the block rails. Such alternating currents in the primarycoils of the receiving transformers energize the secondary coils thereofto deliver signal-controlling alternating currents to the relays, suchas 8, 9, 8 9 8, and 9, one of which is connected in series with thesecondary coil of each receiving transformer. 7

It is obvious that, when a train is present in any block of the system,its wheels and axles must of necessity efiectually short circuit thecurrent of the supply transformer, from one or both of the receivingtransformers of such block, so that one or both of the relays energizedby such receiv ing transformers must of necessity be deenergized when atrain is in the block. When either relay of a given block isdeenergized, the circuit-controlling contacts governed by such relay areof necessity open so as to keep open the circuit of the line relay suchas 12, 12 or 12 at the rear end of the block; but when there is no trainpresent in a given block, for instance when the block 136 is clear oftrains, the supply transformer of such block will effectually energizethe receiving transformers at both ends thereof so as to effectuallyenergize the relays at both ends of the block and close the contacts ofsuch relays, whereupon the circuit of the line relay 12 of such blockwill be closed so as to energize such relay and clear the home signal atthe rear end of the block, while the distant signal located on the samepost will assume clear or danger position according as the block next inadvance is clear or occupied, all of which will appear from aconsideration of the circuits which will now be traced.

When the block BC is clear of trains, as above noted, the tractioncurrent generator I delivers current through the trolley wire K to thebranch conductor 25 connected with such trolley wire at the signalingstation G, and from such conductor 25 the current passes through theresistance 13, conductor 22, contacts 21, 20. controlled by the advancetrack relay 8 of the block BC, and thence through the line conductor 2",line relay 12 at the rear end of the block, conductor 29, contacts 28",27 controlled by the rear track relay 9 of the block BC, and thencethrough the conductor 26 to the section-bonding conductor which joinsthe neutral points of the primary coils 17 and 16 of the receivingtransformers 18 and 15 and thence the current passes through the regularreturn path for traction current already traced back to the, tractiongenerator. Currentin the foregoing circuit of the line relay 12magnetizes the core of such relay with suflicient intensity to bring itsContact fingers 23 and 30 into contact with their respective contactstops 24 and 31". When such contacts are closed the home-signalsemaphore 11 is cleared through the sema-' phore-actuating circuittraceable as follows: from the traction generator I through the trolleywire K, conductor 25 contacts 24:", 28 contacts 30 31 conductor 32 motoror equivalent electric semaphore-actuating device which clears thesemaphore 11 and thence through the conductor 33 to the section-bondingconductor joining the neutral points of the receiving transformer coils17 and 16", and thence back to the traction generator I through theregular return path.

The distant-signal semaphore 10 of the signaling apparatus B must remainin its danger position so long as the block second in advance isoccupied by the train D, but

as soon as the train D emerges from such block, tlic line relay 12 ofthe signaling apparatus C will be energized in the same manner as theline relay 12 of the signaling apparatus B, whereupon such line relay 12will close its contacts 24?, 28 and 31, 30, so as to clear thehome-signal semaphore 11 through agencies corresponding exactly to thoseby which the home-signal semaphore 11 has been cleared; and at the sametime, the closure of the contacts 2 23 will effectually short-circuitthe resistance 13 so as to cut this resistance out of the circuit of theline relay 12 and increase the current strength in such line relaysufficient to attract its distant-signal clearing contact finger 8 intoposition of contact with its cooperating contact stop 35, suchdistant-signal clearing contact finger 3? being, of course, adjusted sothat it cannot respond to the initial energization of the line relaywhich priorly actuates its contact fingers 23 and 30*. hen thedistant-signal clearing contact finger 3 1" is thus actuated, thedistant-signal semaphore 10 is cleared by current in the followingcircuit: from the traction generator I through the trolley wire K,branch conductor 25 contacts :24", 23, contacts 34:, 35", conductor 36*,motor or equivalent device which ac-tuates the semaphore 10, and thencethrough the conductor 33 back to the traction generator through pathsalready traced.

The diagram shows the distant-signal semaphore 10 of the signalingapparatus A already cleared by closure of the distantsignal clearingcontacts 34:, 35, of the line relay 12 of such signaling apparatus A,such line relay 12 being energized to full strength by closure of theontacts 23 2%" of the line relay 12" next in advance, such contacts24:", 23* serving to efi ectually short-circuit the resistance 13 which,of course, is included in the circuit of the line relay 12 until suchcontacts 2 t 23 are closed by energization of the line relay 12 which,in turn depends upon a clear condition of the block BC.

To those versed in the art it will be apparent that the rudiments of myinvention may be utilized in various embodiments difi'ering in specificor particular form and arrangement, all such other embodiments coming,however, fully within the broad principles, scope and purpose of mybroad invention.

hat I claim and desire to secure by Letters Patent is:

1. A home-and-distant railway block signaling system comprisinghome-and-distant signaling apparatuses located at the termini ofsuccessive signaling blocks or sections, for each block two relaysconnected to the track rails substantially at the opposite ends of theblock, for each block a source of signalcontrolling current common toboth relays of the block and connected to the rails thereof at a pointbetween its ends, for each home-and-distant signaling apparatus asignal-controlling circuit in control of such apparatus and extendingthrough the block next in advance thereof and in turn controllable byboth relays of such block to govern the home-signal indication of suchapparatus, and for each signal-controlling circuit means subject tocondition of the block next in advance of such circuit for controllingsuch circuitto govern the distant-signal indication of its signalingapparatus.

2. Ahomeand-distant railway block signaling system comprisinghome-and-distant signaling apparatuses located at the termini oisuccessive signaling blocks or sections,for each block two relaysconnected to the track rails substantially at the opposite endsof theblock, for each block a source of signal-controlling current common toboth relays of the block and connected to the rails thereof at a pointbetween its ends, and for each home-and-distant signaling apparatus asignal-controlling circuit in control of such apparatus and extendingthrough the block next in advance thereof and in turn controllable byboth re lay. of such block to govern the home-signal indication of suchapparatus and controllable also by the signal-controlling circuit of theblock next in advance to govern the distant-signal indication of thehome-and-distant signaling apparatus.

A combined railway electric traffic-com trolling and traction systemcomprising traffic-controlling apparatuses arranged to govern traffic atthe termini of successive blocks or sections of the railway track, atrafficcontrollingcurrent supply transmission line including a source oftratlic-controlling current of given character and extending along therailway, trafiic-controlling current supply transformers having theirprimary coils connected with the transmission line and having theirsecondary coils connected with the rails of the various track sectionsat points between the termini thereof and adapted to act as conductivecross-bonds between such rails for conduction of the traction currenthereinafter mentioned and also adapted to deliver trafiic-controllingcurrent to such track rails, for each section two re ceivingtransformers having their primary 7 coils connected to the rails of thesection at the termini thereof, for each receiving transformer atraffic-controlling relay connected with the secondary transformer oiland arranged in control of one of the traflic-controlling apparatuses,and an electric traction circuit including a source of traction currentdifferent in character from the trafficcontrolling current and includingas return conductors the rails of the successive track sections and theprimary coils of the various receiving transformers.

In testimony whereof I have affixed my signature in presence of twowitnesses.

CLYDE J. COLEMAN. Witnesses ALBERT V. T. DAY, BERNARD CowEN.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. 0."

